Guided rotary shoe



Sept. 1, 1959 J. o. STANDRIDGE I GUIDED ROTARY SHOE Filed June 8, 1956 2 Sheets-Sheet 1 Arm/0mm" 2 Sheets-Sheet 2 dose 0x? Jfcmc/rmye INVENTOR ATTORNEYS J. O. STANDRIDGE Filed June 8, 1956 United States Patent 2,902,261 GUIDED ROTARY SHOE Joseph 0. Standridge, New Iberia, La., assiguor to Houston Oil Field Material Company, Inc., Houston, Tex., a corporation of Delaware Application June 8, 1956, Serial No. 590,209

4 Claims. (Cl. 25-42) This invention relates to a guided rotary shoe and more particularly to a guided rotary shoe in which the shoe is guided over enlargements in diameter of a fish in a well bore.

In the drilling of oil wells and the like, it frequently happens that a length of pipe becomes stuck in the well bore for many reasons, such as twisting oil. the drill string, untimely uncoupling of members of the drill string and the like. It is desirable to recover as much of the pipe left in the well bore as possible to prevent abandoning the well, among other costly operations, andto sal- (age the pipe. i i i One common method utilized in recovering a section off'stuck pipe, sometimes called a fish, is to washover" the fish with a pipe of larger diameter than the fish which pipe is usually called a wash pipe. Located on the lower end of such wash pipe is a tubular device having teeth or other cutting means in the bottom end thereof which tubular device is called a rotary shoe. The purpose of this shoe is to cut away the subsurface formations which often bind the fish in the bore and prevent its removal. v

Mpst rotary shoes are short tubular pieces of steel with thread means at one end for connection to the lower end of the wash pipe and teeth 'in the other end to cut away the formation. As the fish'frequently has conplings, tool joints, collars, and the like which create enlargements from the normal external diameter of the fish and as the inner wall of the rotary shoe usually rides against one portion of the fish, the teeth, upon encountering such enlargements, often cutinto such enlargements thereby; slowing the wasboverjoperation and damaging the fish and shoe.

1f is' therefore'a general object of the, present invention to provide a rotary shoe which is soguided that the cutting'm'eans -of--the shoe will not engage these enlarge.- rfint's inthefish to-such an extent that-damage is caused.

Another object of the present invention is to provide such a guided rotary shoe in which obstruction to flow of drilling fluids is held to a minimum.

A more particular object of the present invention is to provide such a guided rotary shoe including an eccentric guide means located on one portion of the inner wall of the rotary shoe approximate the teeth, said eccentric guide means including cam surfaces to assist passage of the rotary shoe over enlargements in the fish.

And yet another object of the present invention is to provide such a guided rotary shoe which is dependable in use and extremely economical to manufacture.

Other and further objects will be apparent from the following description of examples of a guided rotary shoe constructed in accordance with the invention, and by reference to the accompanying drawings, where like character references designate like parts throughout the several views, and where:

Figure 1 is a vertical sectional elevation of one form of the guided rotary shoe of the present invention illustrating it in use with a wash pipe,

"ice

Figure 2 is an enlarged fragmentary vertical section.

of the lower portion of one form of the present invention illustrating its passage over a tool joint,

Figure 3 is a cross sectional view along the line 3-3 of Figure 2,

Figure 4 is a fragmentary sectional elevation i1lustrating in detail one form of the eccentric guide means of the present invention,

Figure 5 is a view similar to Figure 2 illustrating a modified form of the present invention, and

Figure 6 is a cross sectional view along the line 6- -6 secured in any conventional manner to the wash pipe 14.

or other operating pipe such as through the threaded coupling 17. The cutting means 16 on the lower end of the body 12 may be any conventional cutting means such as the saw teeth 20 best illustrated in Figure 2.

. As best seen in Figures 2, 3, and 4,the eccentric guide means 18 in this form of the invention is a tapered pad 22 in the shape of a parallelogram when viewed as in Figure 4 having a thin leading edge 24 located parallel to and adjacent the leading edge 26 of one of the teeth 20 and having an abrupt trailing edge 28 To give the'desired eccentric action as will be made clear later herein the tapered pad 22 tapers outwardly from the inner wall 19 of the body 12 from the leading edge 24 to the trails.

ing edge 28. The trailing edge 28 is abrupt to give a maximum of free cross sectional area within the interior of body 12.

An'upwardly and outwardly beveled surface 30 is provided on the upper edge of tapered pad 22 so that when the tool 10 is being raised relative to a fish 32, the tapered pad 22 will be carnmed over obstructions such as a tool joint 34 on fish 32. The leading edge 24 of the tapered pad 22. serves as a cam upon rotation and lowering of thetool 10 as will be made more apparent later herein.

As best seen in Figures 2 and 3' the tapered pad 22- projects from the inner wall 19 of the b'ody l2rless than the difference between the internal diameter of the body 12 and the external diameter of enlargements such as a tool joint 34 so there is room for passage of the tapered pad past the enlargements.

As the tapered pad '22 will be subject to considerable wear, it is made of wear resistant material, preferably wear resistant metal such as S.A.E. 4140 and secured to the body 12 by conventional means such as by a fillet weld.

In'o-peration the guided rotary shoe 10 is secured to the lower end of the washpipe 14 and this assembly is lowered into the well bore on the end of a string of conventional drilling pipe, not shown, and internally receives the upper end of the fish 32. As this assembly passes downwardly over the fish 32 the tool 10 is rotated by rotation of the drilling string and drilling fluid is normally forced downwardly in the annular space between the exterior of the fish 32 and the interior of the tool 10 to carry away cuttings, to lubricate, and the like. A portion of the fish 32 usually has the tool 10 riding against. it because of earth formation, bends in the fish, and the like, but as the eccentric guide means 18 of the tool 10 reaches that portion of the fish 32 the eccentric guide means 18 forces the tool 10 outwardly with respect to the fish 32 relieving binding of the tool 10 against the side of the fish. When an abrupt increase in the diameter of the fish is encountered there is already lateral room for the tool 16 to move because of the eccentric action heretofore described which has caused a cutting away of the binding portion of the formation. Upon meeting the increased diameter portion of the fish by the teeth 2% and the leading edge 24 of the tapered pad 22, the rotation of the body 12 and the action of the tapered pad 22 will cause the teeth 20 to move outwardly with respect to the increased diameter portion wherever there is a tendency of the tool 10 to bind against the fish 32 and thus will permit the teeth 20 to pass downwardly over the obstruction.

As the tapered leading edge 24 of the tapered pad 22 is adjacent the leading edge 26 of a tooth 29 this camming action will move the cutting means 16 outwardly from the enlargement on the fish 32 without cutting into the enlargement and thereafter the tool 10 rides downwardly over the enlargement such as the tool joint 34 as, best illustrated in Figure 2.

Upon withdrawal from the well here of the tool 10 the beveled surface 30 permits the tapered pad 22 to ride over downwardly facing obstructions on the fish 32 and the tool may be easily withdrawn.

Referring now to Figures and 6 there is illustrated a modification in which the eccentric guide means 18 is a rounded pad 36 which when viewed in horizontal cross section has an are shaped surface expcsed within the body 12 and when viewed in vertical cross section is in the shape of a truncated triangle so that a flat bearing surface 38 contacts the exterior of the fish 32 when the tool is in the position shown in Figure 5. An upwardly and inwardly beveled surface 40 is provided on the lower portion of rounded pad 36 and a similar beveled surface 42 is provided on the upper portion of rounded pad 36 so that when the rounded pad 36 comes in contact with any abrupt increase in external diameter of the fish 32, such as passing over an end of the tool joint 34 as shown in Figure 5, the body 12 is cammed away from such abrupt increase in diameter permitting the eccentric means 18 to ride over this increased diameter portion.

As the external surface of the rounded pad 36 will be subject to considerable wear it is made of wear resistant material in this modification also. Preferably a mild matrix 42 of mild steel is built up On the inner wall 19 of the body 12 in any conventional means such as by using a mild steel welding rod and an oxy-acetylene flame or an electric arc. Elongate slugs 44 of tungsten carbide-or other hard metal are set vertically in the matrix adjacent to the flat bearing surface 38. Thereafter a wear resistant surface is placed on all exposed portions of the rounded pad 36 in any conventional method such as'by using a welding rod of hard facing material and an oxy-acetylene flame or an electric are.

.4 As thus constructed the hard metal slugs 44 give additional wear resistant surface after the hard facing at the flat bearing surface 38 has been worn away. Of course, other means of making the rounded pad 36 wear resistant could be utilized.

In operation, this modification is used in the same manner as the form shown in Figures 1, 2, 3 and 4 except, as best shown in Figure 5, when an obstruction such as a tool joint 34 is encountered the lower cam surface 40 of the tool encounters this obstruction camming the toolit? away from the obstruction and permitting the tool to pass over the obstruction. Upon withdrawal from the well bore of the tool it} the upper cam surface 42 permits the rounded pad 36 to similarly ride over downwardly facing obstructions and the tool may be easily withdrawn.

From the example given of the present invention it is apparent that it fulfills the stated objects as well as others inherent therein and that changes may be made in details such as in the shape of the eccentric guide means 18. Accordingly, it is desired to be limited only by the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. A guided rotary shoe for cutting around fish in a well bore comprising, a tubular body having an internal diameter greater than the outer diameter of the fish including enlargements thereon, cutting means on the lower end of the body for cutting around the fish, and guide means within the body disposed proximate the cutting means, said guide means including a pad projecting inwardly from the body a distance less than the difierence between the internal diameter of the body and the outer diameter of the fish, and. a guide surface on the pad tapering inwardly away from the body in a direction counter to the direction of rotation of the body, tapering outwardly toward the body adjacent its upper portionand tapering outwardly toward the body adjacent its lower portion.

2. The guided rotary shoe of claim 1 including hard metal slugs disposed in the pad adjacent the surface.

3. The rotary shoe of claim 1 where the guide surface of the pad, in horizontal cross-section, is generally formed in the arc of a circle.

4. The guided rotary shoe of claim 1 in which the leading edge of the guide surface of the pad comprises a. thin leading edge.

References Cited in the file of this patent UNITED STATES PATENTS Henderliter July 14, 1925 

